In various surgical procedures, fasteners in the form of staples or the like are employed for holding tissue portions together to facilitate healing of a wound or incision. For example, a locking staple, having a tongue and groove structure by which the staple is locked, is disclosed in U.S. Pat. No. 2,881,762. A metal staple especially adapted for ligating blood vessels is disclosed in U.S. Pat. No. 3,079,608. International Patent Application No. PCT/SU79/00049 discloses a variety of fastening devices and instruments for performing circular anastomoses on the large intestine. The aforementioned disclosures serve as examples of a wide variety of tissue fastening devices and techniques that may be employed in general and/or specific surgical situations.
One common type of fastening device for joining or holding together soft tissue portions is the generally "U"-shaped staple which is typically fabricated from a suitable metal. Such staples, although generally described as having two legs joined by a link to define a "U"-shape when unclinched, may also be regarded as having a configuration of an "open" loop when unclinched. The legs need not necessarily be parallel but are typically adapted for penetrating the tissue portions and for receiving between them some of the tissue material.
Other examples of U-shaped or open loop staples, as well as of methods and instruments for applying such staples to tissue, are disclosed in U.S. Pat. Nos. 3,252,643, 3,482,428, 3,692,224, 3,790,057, 3,795,034, 3,889,683, 4,198,982, 4,316,468, and 4,319,576.
Other tissue fastening devices have been proposed and differ from staples per se in that these other devices may have a plurality of components and do not have to be clinched in the manner used to set a staple. One such device is disclosed in U.S. Pat. No. 4,060,089 and includes a fastener strip provided with a plurality of longitudinally spaced, parallel prongs which are adapted to penetrate two overlapped tissue portions from one side so that the distal ends of the prongs project from the other side of the tissue portions.
The fastener device further includes a retainer strip which is adapted to be placed on the other side of the tissue portions opposite the fastener strip to engage the ends of the projecting fastener strip prongs and thus secure the tissue portions tightly between the fastener strip and the retainer strip. The fastener strip prongs each include a plurality of spaced-apart engaging members for engaging the retainer strip at a desired position relative to the prongs. This provides for the capability of adjusting the distance between the fastener strip and the retainer strip. Such a fastening device may be fabricated from a biodegradable or absorbable material.
Other patents, such as U.S. Pat. Nos. 2,286,578 and 3,638,654, disclose instruments for applying flexible sutures with needles that are inserted into the tissue portions.
Other types of fasteners that include a fastening member with legs joined by a link and secured in a retaining receiver on one side of an incision are disclosed in the following concurrently filed, copending U.S. patent applications assigned to the assignee of the instant application.
(1) Ser. No. 506,151, entitled "Two-Piece Tissue Fastener With Coinable Leg Staple And Retaining Receiver And Method And Instrument For Applying Same";
(2) Ser. No. 506,088, entitled "Two-Piece Tissue Fastener With Toothed Leg Staple And Retaining Receiver"; and
(3) Ser. No. 506,083, entitled "Two-Piece Tissue Fastener With Bent Leg Staple And Retaining Receiver";
(4) Ser. No. 506,087, entitled "Two-Piece Tissue Fastener With Non-Reentry Bent Leg Staple And Retaining Receiver";
(5) Ser. No. 506,082, entitled "Two-Piece Tissue Fastener With Compressible Leg Staple And Retaining Receiver";
(6) Ser. No. 506,145, entitled "Two-Piece Tissue Fastener With Wedged Leg Staple And Retaining Receiver"; and
(7) Ser. No. 506,144, entitled "Two-Piece Tissue Fastener With Deformable Retaining Receiver".
The fasteners disclosed in the above-identified copending patent applications are also illustrated and briefly described herein. These fasteners may be applied to the tissue portions by forcing the fastening members directly into the tissue portions with a suitable instrument so that the fastening member legs protrude from the tissue portions on one side of the incision where they are engaged by the receiver.
When the fastening member legs are forced through the tissue portions, care must be taken to prevent deflection of the legs by the tissue. Such deflection could prevent receipt of the legs in the fastener. Although these fasteners work well in many applications, in some situations, as with relatively tough tissue and relatively slender legs, prevention of such deflection may be difficult.
U.S. Pat. No. 4,006,747 discloses the application of a flexible fastener to tissue by means of a slotted, hollow, straight, needle with a plunger for pushing the fastener through the needle. The application of a similar fastener in a non-surgical situation is disclosed in U.S. Pat. No. 4,215,807.
This type of fastener, for use in joining tissue, is also disclosed in the pending patent application Ser. Nos. 506,151, 506,088, 506,083, 506,087, 506,082, 506,145, and 506,144, filed June 20, 1983, June 20, 1983, June 20, 1983, June 20, 1983, June 20, 1983, June 20, 1983, and June 20, 1983, respectively, which are all assigned to the assignee of the instant application. This type of fastener comprises a pair of anchoring means or legs joined by a flexible link or filament. Each leg or anchoring means has two ends and is connected intermediate of its two ends to the filament or link. These pending applications also identify U.S. patents disclosing other types of fasteners, along with methods and instruments for applying such other types of fasteners.
According to the methods disclosed in the pending patent applications identified in the preceding paragraph, an instrument having a single, hollow, slotted, curved needle is used for applying the fastener. The tissue portions to be joined are overlapped in face-to-face relationship and penetrated from one side of the wound or incision by the needle. The needle is inserted so that the distal end of the needle projects from the other side.
One of the fastener legs is inserted into the needle on the first side of the wound or incision and is pushed through the needle so that the one leg is discharged from the needle on the other side of the wound or incision. Then the needle is pulled back out of the tissue leaving the fastener in the tissue with the link transversing the wound or incision through the tissue portions and with the legs lying on either side of the wound or incision.
U.S. Pat. No. 3,716,058 discloses a barbed surgical suture and a special needle used for inserting the suture in position within tissue. The needle is hollow and has a lengthwise notch or channel for carrying the suture. The needle, with one end of the suture mounted therein, is inserted into the tissue and then the needle is removed rearwardly from the tissue to leave the one end of the suture in the tissue. The same procedure is then repeated for the other end of the suture.
A non-surgical method and apparatus are disclosed in U.S. Pat. No. 3,875,648 for applying a similarly shaped flexible fastener to hold two layers of garment material together. The apparatus includes a pair of hollow, slotted needles, each with a reciprocative pusher member disposed therein.
The fastener is applied by placing each leg in one of the hollow slotted needles on a first side of the material layers and penetrating the material layers with the needles. Next, the legs are pushed through the needles to the other side of the material layers with a portion of the fastener filament remaining on the first side of the material layers to hold the layers together after withdrawal of the needles.
Although many of the above-discussed types of tissue fastening devices and techniques are satisfactory in various applications, there is a need to provide an improved method for fastening mammalian tissue with reduced trauma.
It would also be desirable to provide an improved fastening method for use with fasteners fabricated from absorbable materials that can provide primary approximation of the tissue edges to insure that the tissue edges are in continuous contact. Further, such an improved method should provide a desired amount of hemostatic compression to minimize bleeding, but allow some collateral blood circulation to the wound or incision edges of the tissue to promote healing. In addition, such an improved method should have the capability to accommodate varying tissue thicknesses and should leave as little tissue cuff or margin as possible in effecting the joining of the tissue.
Further, it would be beneficial if such an improved fastening method was compatible with fasteners that are fabricated with (1) as small a size as possible to minimize dosage, (2) a minimum of sharp edges or protrusions, and (3) a configuration that does not form, or contribute to the formation of, pockets of infection in the tissue.
Further, such an improved fastening method would desirably provide the surgeon with tactile feedback and compensating control during the application of the fastener.
It would also be advantageous to provide a fastening method that would readily accommodate application by means of an appropriately designed instrument.
Finally, it would be desirable to provide a relatively simple, yet effective and rapidly operating instrument for applying a variety of fasteners according to such an improved method. When used to apply two legged fastening members to tissue with retaining receivers, such an instrument and improved method should desirably prevent deflection of the fastening member legs passing through the tissue and should provide proper alignment of the fastening member legs with the receiver.